//
// Created by Thinkpad on 2025/10/30.
//

#include <iostream>
using namespace std;

void say_age(const int age);

int main() {
    int age {23};
    cout << "age - before :" << age << endl;
    say_age(age);
    cout << "age - after :" << age << endl;
    return 0;
}


void say_age(const int age) {
    // ++age;  // changing the copy.Error!
    cout << "hello!you are " << age << " years old." << endl;
}